<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
            outline: 0;
        }
        /* .clearfix:after{
         
           display: block;
           clear: both;
        } */
        .orange{
            background-color: orange;
        }
        .w150{
            width: 150px;
            height: 150px;
        }
        main{  
            background-color: green;
            height: 100px; 
            float: left;
            width: 100%;
            
        }
        .grail{
            padding: 0 150px;
        }
        .left{
            float: left;
            margin-left: -100%;
            position: relative;
            left: -150px;
        }
        .right{
            float: left;
            /* margin-right: -100%; */
            margin-left: -150px;
            position: relative;
            right: -150px;
        }
    </style>
</head>
<body>
    <div class="layout">
        <h4>圣杯布局</h4>
    <section class="grail clearfix">
        <main class="green">main</main>
        <aside class="w150 left orange">aside1</aside>
        <aside class="w150 right orange">aside</aside>
    </section>
    </div>
    
</body>
</html>